USP Told 'Big Four' Heavy Metals Should Take Priority in Compendial Revision

Go after 'big four' heavy metals first in revising outdated compendial standard, USP told. Start with arsenic, cadmium, lead and mercury, not all 31 listed metals, industry says in response to stimuli article, which would let them choose methods for meeting performance-based standards. Residual solvents chapter proposed as template. EMEA catalyst guideline lauded. Some want dosing frequency considered in setting toxicology limits.